Transport and assembly system and method for composite barrel segments

ABSTRACT

A barrel assembly for a composite structure includes a barrel of composite material, a first end ring, and a mid support. The barrel of composite material has a first end, an interior surface and an outer surface, and the first end ring is removably attached to the first end. The first end ring has a perimeter that is substantially congruent with the first end, and is configured to maintain a shape of the barrel. The mid support is removably disposed within the barrel, and has a plurality of spokes extending outwardly from a central hub to contact the interior surface, to maintain a shape of the barrel.

PRIORITY CLAIM

The present application is a continuation of U.S. patent applicationSer. No. 13/622,035, filed on Sep. 18, 2012 and entitled TRANSPORT ANDASSEMBLY SYSTEM AND METHOD FOR COMPOSITE BARREL SEGMENTS, the disclosureof which is incorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

The present invention relates generally to the support and transport ofcomposite barrel segments during manufacture and assembly. Moreparticularly, the present invention relates to a system and method forsupporting the shape of composite barrel segments, such as aircraftfuselage segments, from the point of mandrel removal through assemblywith other barrel segments.

Background

In recent years, aircraft manufacturers have developed aircraft designsand aircraft fabrication methods that make greater use of carbon fibercomposite materials and the like (“composite materials” or “CFCM”), suchas graphite/epoxy and carbon fiber reinforced plastic (“CFRP”).Composite materials are significantly lighter than traditional aircraftmaterials (e.g. aluminum, titanium, steel and alloys of these), and canprovide high strength with low weight, allowing lighter, more fuelefficient aircraft. In some newer aircraft, for example, the majority ofthe primary structure, including the fuselage and wing, is made ofcomposite materials. By volume, some new aircraft can be about 80%composite materials.

Since composite materials have different characteristics than sometraditional aircraft materials, new facilities, equipment and handlingmethods have been developed. For example, whereas traditional aircraftmanufacturing involves attaching fuselage skin sections (e.g. aluminumsheets) to a metal aircraft frame, large barrel-shaped fuselage sectionsof composite material can be built as a single unit on an inner moldline mandrel. Such fuselage sections can be quite large, and aretypically fabricated without an internal frame. After curing of thecomposite material, the inner mandrel is removed, and the fuselagesection can be assembled with other fuselage sections.

Since structures fabricated from composite materials have differentcharacteristics than many traditional aircraft materials, new equipmentand methods have been developed for carrying and holding such structuresafter removal from a mandrel. One challenge presented by devices forholding and transporting large, frameless composite barrel sectionsafter removal from a mandrel is controlling the shape of the barrelwithin geometric tolerances during subsequent manufacturing operationsor during storage.

The present application seeks to address one or more of the aboveissues.

SUMMARY

It has been recognized that it would be advantageous to develop systemsand methods for controlling the shape of a composite barrel sectionwithin geometric tolerances during movement and during storage.

It has also been recognized that it would be advantageous to havesystems and methods for controlling the shape of a composite barrelsection that can be quickly and easily installed or removed.

It has also been recognized that it would be advantageous to havesystems and methods for accurately controlling the shape of a compositebarrel section within a dimensional tolerance that support furtherfabrication and assembly steps.

In accordance with one embodiment thereof, the present inventionprovides a barrel assembly for a composite structure. The barrelassembly includes a barrel of composite material, a first end ring, anda mid support. The barrel has a first end, an interior surface and anouter surface, and the first end ring is removably attached to the firstend. The first end ring has a perimeter that is congruent with the firstend, and is configured to maintain a circumferential shape of thebarrel. The mid support is removably disposed within the barrel, and hasplurality of spokes extending outwardly from a central hub to contactthe interior surface, to maintain a shape of the barrel.

In accordance with another aspect thereof, the invention provides asystem for moving a composite aircraft fuselage section having agenerally cylindrical shape, two opposite ends, an inner surface and anouter surface. The system includes a pair of end rings, at least twosupports disposable within the fuselage section, and a moveable cart,configured to support the fuselage section. The end rings are removablyattachable to the opposite ends of the fuselage section, and configuredto maintain a shape of the fuselage section, each end ring having aperimeter that is congruent with the respective end. The at least twosupports have a plurality of adjustable spokes that are extendableoutwardly from a central hub to contact the inner surface, to maintain ashape of the fuselage section. The moveable cart has a plurality ofsupports configured to contact and support the outer surface tosubstantially retain a nominal shape of the fuselage section.

In accordance with yet another aspect thereof, the invention provides amethod for transporting a composite barrel. The method includesattaching first and second end rings at first and second ends of acomposite barrel, each end ring having a perimeter that is congruentwith the respective end, installing at least two supports against aninner surface of the composite barrel, the supports comprising a hub anda plurality of adjustable spokes extending from the hub to the innersurface, and placing the composite barrel upon shape-confirming supportson a moveable platform.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features and advantages of the invention will be apparentfrom the detailed description which follows, taken in conjunction withthe accompanying drawings, which together illustrate, by way of example,features of the invention, and wherein:

FIG. 1 is a perspective view of an aircraft barrel section supported bya mandrel mounted on a pair of mandrel support rings;

FIG. 2 is a perspective view of a six-section mandrel for forming anaircraft barrel section;

FIG. 3 is a rear perspective view of an aircraft barrel section with arear end support ring installed, and a front end support ring positionednear the front perimeter edge of the barrel section;

FIG. 4 is a front perspective view of an aircraft barrel section with arear end support ring and internal support rings installed, and a frontend support ring positioned near the front perimeter edge of the barrelsection;

FIG. 5 is a front perspective view of an aircraft barrel section two endsupport rings and two internal support rings installed;

FIG. 6 is an exploded perspective view of an aircraft barrel sectionshowing one internal support ring installed and another outside thebarrel section;

FIG. 7 is a perspective view of a pair of internal support ringsconnected by three longitudinal members;

FIG. 8 is a rear perspective view of an aircraft barrel section, withinternal and end rings installed, on a moveable transport cart;

FIG. 9 is a front perspective view of an aircraft barrel section withinternal and end rings installed on a moveable transport cart;

FIG. 10 is a front perspective view of an aircraft barrel section withinternal and end rings, installed on a moveable transport cart;

FIG. 11 is flowchart of an embodiment of a method for stabilizing acured composite fuselage barrel according to the present disclosure;

FIG. 12 is a flow diagram of aircraft production and servicemethodology; and

FIG. 13 is a block diagram of an aircraft.

DETAILED DESCRIPTION

Reference will now be made to exemplary embodiments illustrated in thedrawings, and specific language will be used herein to describe thesame. It will nevertheless be understood that no limitation of the scopeof the invention is thereby intended. Alterations and furthermodifications of the inventive features illustrated herein, andadditional applications of the principles of the inventions asillustrated herein, which would occur to one skilled in the relevant artand having possession of this disclosure, are to be considered withinthe scope of the invention.

As noted above, large barrel-shaped fuselage sections of compositematerial can be fabricated on a mandrel having a size and shape thatmatches the desired inner mold line of the composite shape. After curingof the composite material, the inner mandrel is then removed inpreparation for further manufacturing and assembly steps. Such fuselagesections can be quite large, and are frequently initially assembledwithout an internal frame structure.

A composite barrel section without an internal frame in post-curecondition may not be as stiff as desired for transport to subsequentmanufacturing operations. Consequently, new equipment and methods havebeen developed in the aircraft industry for carrying and holdingcomposite fuselage sections after removal from a mandrel. After removalfrom the mandrel, however, controlling the shape of the barrel withingeometric tolerances during transport (e.g. from cell to cell duringassembly) and/or during storage presents some challenges.

Some prior methods for holding and transporting large composite barrelsections may not maintain the geometric shape of the section as desired.For example, composite barrel sections can be attached (e.g. clamped) toend stabilizer rings that match the geometric shape of the ends of thebarrel section but do not maintain geometrical dimensioning andtolerancing (“GD&T”). Such, stabilizer rings may be attached to anassembly cart for moving the barrel section from point to point in anassembly process. Unfortunately, the use of end stabilizer rings alonemay not hold the barrel section shape within desired geometrictolerances. This can result in increased labor costs during installationof frame members and other appurtenances, for example, or involvereworking in order to join the barrel section to an adjacent barrelsection. Advantageously, the system and method disclosed herein helps toaddress these issues and is believed to improve the quality of joints inadjacent barrel sections and to improve the quality of frameinstallation.

Many types of composite structures are fabricated using a mandrel, onwhich carbon fiber strands are wound and then impregnated with epoxyresin, or pre-impregnated carbon fiber fabric, tape, and/or tows arelaid up, and then cured. Shown in FIG. 1 is a perspective view of anaircraft barrel section 100 supported by a six-piece removable innermandrel 102. A perspective view of the six-section mandrel 102 is shownin FIG. 2. While this particular mandrel 102 has a tapered cylindricalshape, and is designed for fabrication of a tapered rearward segment ofan aircraft fuselage, this is only one exemplary configuration. It willbe apparent that other mandrel shapes and configurations can be providedfor fabricating barrel sections of a variety of shapes and for a varietyof applications. The barrel sections shown and described herein have agenerally cylindrical shape. As used herein, the term “generallycylindrical” is intended to include a wide variety of cylindrical orcylinder-like shapes, including cylinders that are tapered or irregular,cylinders that are not circular in cross section at any given point, andother possible variations.

The sections 104 a-104 f of the mandrel are removably joined alonglongitudinal seams 106, and are attachable at their fore end 108 and aftend 110 to circular mandrel support rings 112, which are mounted to aroller support frame 114. In one embodiment the mandrel support ringsare of an iron-nickel alloy, which has good dimensional stability withtemperature changes. However, other materials can also be used for themandrel support rings, and they can be configured differently from theconfiguration shown in the drawings. The roller support frame 114 andmandrel support rings 112 allow the mandrel 102 to be axially rotatedduring assembly build-up of the barrel section 100. The entire assemblyof the mandrel 102 and support frame 114 can be moveable so that it canbe placed in an autoclave (not shown) for heat curing after initiallayup of the composite barrel section 100. It is to be understood thatthe mandrel configuration and method of composite barrel fabricationthat are shown and described herein are only one example of suitablesystems and methods. Other methods and systems can also be used forfabricating a composite barrel, and the present disclosure is notlimited to one particular method or system.

Once the composite barrel section 100 is fabricated and cured, themandrel 102 can be removed from within the barrel section 100. Theadjacent longitudinal segments 104 of the mandrel 102 can be detachedfrom the mandrel support rings 112 and removed along the seams 106, andthe mandrel sections 104 can be withdrawn one-by-one from against theinner surface of the barrel section 100. Those of skill in the art willappreciate that this description is general in nature, and that therecan be many additional detailed operational steps and apparatus involvedin this process. It will be apparent that removal of the mandrel 102will also remove the structure that supports the barrel section 100 uponthe mandrel support rings 112. Consequently, temporary supports (notshown) can be used to support the curved barrel section 100 while themandrel 102 is being removed from within it.

Viewing FIGS. 3-6, after the mandrel 102 has been removed, orconcurrently with removal of the mandrel sections, a pair of end supportrings 120, 122 can be attached to the fore end 124 and aft end 126 ofthe barrel section 100, respectively. A barrel section 100 with one rearend ring 122 attached and another ring 102 positioned near itsattachment point at the front end 124 of the barrel section 100 isprovided in FIG. 3. The end rings 122, 124 can be installed immediatelyafter mandrel removal, and help maintain the barrel shape withinengineering tolerances throughout subsequent assembly and transport ofthe barrel section 100.

The end support rings 120, 122 are made up of a series of ring segments,indicated generally by numeral 128, that removably attach to each other.The assembled end rings define a perimeter that is congruent (i.e. samesize and shape) with the respective end 124, 126 of the barrel section100. In one embodiment, the end support ring segments include a slot130, which defines the nominal barrel shape of the perimeter of therespective end 124, 126, within acceptable geometric tolerances. ViewingFIG. 3 in particular, the front edge 124 of the barrel section 100 fitsinto the slot 130, and the front end ring 120 can be attached to thebarrel section with clamps (not shown). This allows the complete ring tohold the shape of the barrel section at its fore and aft ends.

Each segment 128 of the end support rings 120, 122 shown in the figuresinclude radial spokes 132, which are each removably attached to an innerring segment 134 and an outer ring segment 136. Elements 128, 134 and136 are commonly labeled in both the fore end ring 120 and aft end ring122 because of their similar shape and function, even though thesestructures can be of different size and shape in the respective endrings. For simplicity, the various parts of only some of the ringsegments 128 are labeled in any one figure. The inner and outer ringsegments 134, 136 associated with a given spoke 132 are removablyattachable to the corresponding segments of the next adjacent ringsegment around the circumference of the ring 120, 122, so that theentire end support ring can be assembled in place from multiple separatepieces, and dismantled in a similar way, and so that any or all of thespokes 132 and the inner ring 134 can be selectively removed, asdesired. This configuration retains dimensional accuracy of the barrelduring mandrel extraction and barrel storage, while providingflexibility for subsequent manufacturing processes.

While the end support rings 120, 122 shown in FIG. 3 include sixsegments 128, it is to be appreciated that end support rings with agreater or lesser number of segments (e.g. five segments, eightsegments, etc.) can also be used. The number of segments 128 in the endring can match the number of mandrel segments 104. For example, a sixsegment end ring 120, 122 can be used where a six segment mandrel 102 isused for fabrication of the barrel section 100. It is also to beappreciated that the end support rings 120, 122 can be configured todefine a circular shape as shown in the figures, or some other desiredshape. For example, in the embodiment shown in FIG. 3 the aircraftfuselage barrel section 100 has a substantially circular cross-sectionat each of the fore and aft ends 124, 126, as is quite common. However,an end support ring 120, 122 can be configured to match a non-circularcross-section also, which can be found in aircraft and other structuresthat include composite barrel sections.

The end rings 120, 122 help maintain the defined barrel shape withindesired tolerances during the assembly process. They also allow for anincrease in process control capability. For example, without end ringsthat preserve the geometric shape of the barrel section, rework of thecomposite material may be undertaken in order to achieve the definedinner mold line surface. The end rings 120, 122 can remain in place aslong as desired to help maintain the shape of the barrel section 100,which can be until the point of installation of frame components orother structure which spatially conflicts with the rings.Advantageously, the installation of frame components and otherstructures within the barrel section 100 will tend to stiffen andstrengthen the barrel section, gradually supplanting the function of theend rings 120, 122.

Additionally, the entire end ring 120, 122 or individual segments of itcan be removed as desired to provide accessibility, such as for assemblyor other operations in a given region inside the barrel section, andlater replaced if desired. For example, as shown in FIGS. 6 and 10, thespokes 132 and the inner ring 134 can be removed from the fore-end ringassembly 120, to provide access to the interior of the barrel 100. Thisleaves the outer ring 136 in place, which continues to provide strengthand geometrical control around the perimeter of the front edge 124 ofthe barrel section until such time as the internal portions of the endring 120 are reinstalled, or the barrel section 100 is attached to anadjacent barrel section, for example. Finally the end rings 120, 122will be removed before a given barrel section 100 is attached to anadjacent barrel section at the particular end (i.e. fore or aft).

In addition to the end support rings 120, 122, the system and methoddisclosed herein also provides an internal or “mid” support ringassembly 140, which is shown in FIGS. 4-7. An internal support ringassembly 140 can include one or more individual spoked rings 142, eachincluding a plurality of outwardly extending spokes 144 that areremovably attachable to a central ring or hub 146. As with the end rings120, 122, the number of spokes 144 associated with each spoked ring 142and the spacing between spokes can vary. While internal support rings142 are shown in the figures having eight spokes 144, a greater orlesser number of spokes can be associated with these devices. The spokes144 can be configured to telescope in length, so that they can beadjusted to conform to barrel sections of different sizes and shapes, orto different longitudinal positions within a barrel section having atapering size. The spokes 144 can include a bearing surface, such as abearing pad (not shown), on their distal end 148, which directly abutsthe interior surface 152 of the barrel section 100. The configuration ofthe bearing pad, including its size, shape, functionality and materialsof construction, can be selected by one of skill in the art tofacilitate barrel shape control and other desired characteristics.

The internal support ring assembly 140 can include multiple internalsupport rings 142, which are attached to each other with longitudinalmembers 154 (e.g. rods). The longitudinal members are shown in FIGS. 7and 9. The longitudinal members 154 can be configured to hold thecentral rings or hubs 146 substantially parallel to each other and at adesired distance, so that the longitudinal members 154 and the rings 146are perpendicular to each other. This allows the longitudinal members154 to define a horizontal datum, substantially parallel to thelongitudinal axis of the barrel 100, and the spoked rings 142 and thespokes 144 to each define a vertical datum that is perpendicular to thelongitudinal axis of the barrel. When the spokes 144 are attached to thecentral rings 146 and placed in abutting contact with the curvedinterior surface 152 of the barrel section 100 (which defines a thirddatum), a three-datum geometric control configuration is created. Thishelps maintain the geometric shape of the barrel section 100 better thanend rings alone, and helps prevent sagging and flexure of the barrelsection 100. The interior support ring assembly 140 helps to control theinterior nominal shape of barrel 100.

The adjacent interior spoked rings 142, being connected to each otherand adjustable between stations (i.e. fore and aft) help to maintain thenominal shape of the barrel 100 during frame installation or otheroperations. The spokes 144 of the interior support assembly 140 aretelescopingly adjustable to a repeatable state to support the internalmold line shape within engineering tolerances. The internal supportrings are also moveable within the barrel 100 from station-to-station tomaintain the barrel shape as frames and other components are installed.

The order of installation of the internal support assembly 140 can vary.For example, the internal support assembly 140 can be installed beforeone or both of the end rings 120, 122 are attached to the ends of thebarrel section 100. Alternatively, the end rings 120, 122 can beattached first, and the internal support assembly 140 can be installedafterward. For example, for an aircraft fuselage section having avariety of openings, as shown in the figures herein, the rings 146,spokes 144 and longitudinal members 154 can be inserted through anopening in the barrel section (e.g. a door opening) after the end ringsare in place, and assembled inside the barrel section. It is to beunderstood that the sequence of installation and/or removal of variousportions of the system shown herein can vary from situation tosituation.

This configuration of the end rings 120, 122 and the internal spokeassemblies 140 provides barrel interface tooling that is controlled byremovable structure to control the exterior shape of the barrel 100within engineering tolerances. Advantageously, the end rings 120, 122and spoke rings 142 are reusable barrel after barrel. Additionally, theinternal spoke shape control tooling can be installed in a given barrelsegment 100 immediately after curing of the barrel segment (i.e.immediately after mandrel removal) and before further product assemblybegins. Workers can begin the assembly process by installing productparts upon or within the barrel sections while the spokes are in place.Later the spokes can be removed by workers without disrupting productassembly.

With the end rings 120, 122 and internal supports 140 in place, thestabilized barrel section 100 can be transported between variousassembly points and/or placed in a storage location upon a moveabledatum controlled transport cart. Three views of an embodiment of amoveable transport cart 700 for a composite barrel segment 100 are shownin FIGS. 7-9. The cart 700 generally includes a frame 702 that issupported on wheels 704, with a plurality of upstanding supports 706configured to contact and support the outer surface 160 of the barrel100 to substantially retain its nominal shape. The upstanding supports706 of the cart 700 can substantially conform to a shape of the outersurface of the composite barrel 100 in an unconstrained condition, whichsecures the barrel reference to engineering tolerances. In oneembodiment, the upstanding supports 706 conform to half a circumferenceof the composite barrel 100 outer surface 160. Where the barrel shapeincludes a taper, as shown in the figures, the curvature of the interiormating surfaces of the upstanding supports can vary accordingly. Thecart 700 and the barrel section 100 can also include devices, such asmarkings, etc., to facilitate placement of the barrel section on thecart in a desired location and orientation. A variety of such devicescan be conceived by those of skill in the art.

Any number of upstanding supports 706 can be used. The upstandingsupports thus provide a shape tool, holding the barrel 100 withinengineering tolerances during movement from one work cell to anotherwhile maintaining the desired geometric configuration. The upstandingsupports 706 can be attached to each other by longitudinal rods 708,which help ensure the position of these supports and provide additionalgeometric control. Viewing FIG. 10, this configuration of the cart 700helps facilitate movement of the barrel section 100 to any desired workstation 710, where workers 712 can perform any desired manufacturing orassembly operation upon the barrel section. In FIG. 10, the workstation710 includes a platform that can be extended into the barrel section 100to allow the workers 712 to install frame members and/or othercomponents, or perform other operations therein. As discussed above, forthis type of interior work station, the spokes 132 and central ring 134of the end ring 120 at the fore end of the barrel 100 can be removed,leaving only the perimeter ring 136 at that end of the barrel 100.Likewise, the interior support assembly 140 can be partially orcompletely removed to allow insertion of the platform. It is to beappreciated that a wide variety of types of work stations can beemployed in the manufacturing and assembly process, and the work station710 shown in FIG. 10 is a simplified representation of only one type ofwork station.

In view of the above, one embodiment of a method 1100 for transporting acomposite barrel in accordance with the present disclosure is outlinedin the flowchart of FIG. 11. It is to be understood that the stepsoutlined in FIG. 11 can be performed in a different order than shown,and, further, while certain variations in the order of the steps arediscussed herein, other variations can also be used. This embodiment ofthe method can be described as including the steps of providing acomposite barrel section 1102 upon a mandrel, then removing the mandrelsections from against the inner surface of the composite barrel 1104.The mandrel section can be sequentially removed, and this can be doneprior to or concurrently with the step of attaching first and second endrings 1106 in the barrel section. Interior or “mid” support rings arealso attached 1108 against an inner surface of the composite barrel, thesupports including a hub and a plurality of adjustable spokes extendingfrom the hub to the inner surface. Attaching the mid supports caninclude longitudinally affixing at least two supports in substantiallyparallel planes that are substantially perpendicular to the innersurface of the barrel.

The composite barrel is then placed upon shape-conforming supports on amoveable platform or cart 1110, which can then be moved from place toplace as needed 1112, such as between work positions that are configuredfor installing components in or to the barrel section 1114, orperforming other manufacturing or assembly operations on the compositebarrel. Moving the cart from place to place and performing additionalmanufacturing actions on or to it can be performed repeatedly, asindicated by the arrow 1116.

At a suitable time, typically at some point during installation of framemembers and other components within the barrel section 1114, the endsupport rings can be removed 1118 from the barrel section in preparationfor ultimate connection of the barrel section with another barrelsection 1122. The mid support rings and their spokes can also be removed1120 (perhaps only partially at first) at some point during installationof components in or to the barrel section. This will presumably bebefore the barrel section is attached to another barrel section, thoughit could conceivably occur after such attachment. Moreover, the order ofremoval of the mid supports and end rings can vary, and since the spokesof the mid supports are individually removable and the segments of theend rings are detachable, the end rings and mid supports can becompletely or partially removed at any time, as desired. For example,one or more but not all of the spokes of a given mid support can beremoved at any time during the manufacturing process as desired tofacilitate various manufacturing or assembly operations within thebarrel section. Additionally, some assembly processes can be performedby workers while some or all of the spokes are in place, and in certaincases spokes can be selectively removed by workers without disruptingproduct assembly.

When all desired preparations have been made, the composite barrel canbe positioned and aligned in an opposing edge-to-edge circumferentialalignment with an adjacent composite barrel 1122, to facilitateattachment or mating of the composite barrel 1124 with the adjacentcomposite barrel. After mating of the barrel section, additionalcomponents can be installed in or on the barrel section 1126 to continuethe manufacturing and assembly process, and this can be performedrepeatedly, as indicated by the arrow 1128.

Advantageously, the system and method disclosed herein helps hold acomposite barrel within engineering tolerances without a floor gridinstallation, and allows the barrel to be moved from cell to cell andposition to position. This system and method helps maintain the shape ofthe barrel within engineering tolerances from cell to cell and duringstorage. The system and method disclosed herein allows for repeatableconditions for maintaining the internal mold line shape of a compositebarrel within engineering tolerances using a 3 datum control, whichhelps to maintain the barrel shape during the assembly process. The cartassembly combined with shape rings and internal barrel supports alsohelps reduce preload stresses in frames and other structures that areattached to the barrel section during assembly. It is believed that thisapproach can improve the quality of joints between barrels andfacilitate the installation of barrel interface assemblies. It isbelieved that this approach has the potential to significantly reduceassembly time by reducing rework, and can also promote worker safety.

Embodiments of the disclosure may be described in the context of anaircraft manufacturing and service method 1200 as shown in FIG. 12 andan aircraft 1202 as shown in FIG. 12. During pre-production, exemplarymethod 1200 may include specification and design 1204 of the aircraft1202 and material procurement 1206. During production, component andsubassembly manufacturing 1208 and system integration 1210 of theaircraft 1202 takes place. Thereafter, the aircraft 1202 may go throughcertification and delivery 1212 in order to be placed in service 1214.While in service by a customer, the aircraft 1202 is scheduled forroutine maintenance and service 416 (which may also includemodification, reconfiguration, refurbishment, and so on).

Each of the processes of method 1200 may be performed or carried out bya system integrator, a third party, and/or an operator (e.g., acustomer). For the purposes of this description, a system integrator mayinclude without limitation any number of aircraft manufacturers andmajor-system subcontractors; a third party may include withoutlimitation any number of venders, subcontractors, and suppliers; and anoperator may be an airline, leasing company, military entity, serviceorganization, and so on.

As shown in FIG. 15, the aircraft 1202 produced by exemplary method 1200may include an airframe 1218 with a plurality of systems 1220 and aninterior 1222. Examples of high-level systems 1220 include one or moreof a propulsion system 1224, an electrical system 1226, a hydraulicsystem 1228, and an environmental system 1230. Any number of othersystems may be included. Although an aerospace example is shown, theprinciples of the invention may be applied to other industries, such asthe automotive industry.

Apparatus and methods embodied herein may be employed during any one ormore of the stages of the production and service method 1200. Forexample, components or subassemblies corresponding to production process1208 may be fabricated or manufactured in a manner similar to componentsor subassemblies produced while the aircraft 1202 is in service. Also,one or more apparatus embodiments, method embodiments, or a combinationthereof may be utilized during the production stages 1208 and 1210, forexample, by substantially expediting assembly of or reducing the cost ofan aircraft 1202. Similarly, one or more of apparatus embodiments,method embodiments, or a combination thereof may be utilized while theaircraft 1202 is in service, for example and without limitation, tomaintenance and service 1216.

It is to be understood that the above-referenced arrangements areillustrative of the application of the principles of the presentinvention. It will be apparent to those of ordinary skill in the artthat numerous modifications can be made without departing from theprinciples and concepts of the invention as set forth in the claims.

What is claimed is:
 1. A tool for maintaining a shape of a compositebarrel having a first end, a second end, an inner surface and an outersurface, the tool comprising: a first end ring, removably attachable toa first end of the composite barrel, having a perimeter that issubstantially congruent with the first end, configured to maintain ashape of the barrel; and a mid support, removably disposable within thecomposite barrel, having a plurality of spokes extending outwardly froma central hub to contact the inner surface, to maintain a shape of thebarrel.
 2. The tool of claim 1, wherein the mid support comprises atleast two supports having a plurality of spokes extending outwardly froma central hub, the spokes being longitudinally affixed in substantiallyparallel planes, and the at least two supports being disposedsubstantially perpendicularly with respect to the inner surface of thecomposite barrel.
 3. The tool of claim 2, further comprising alongitudinal member, connected between the central hubs, defining ahorizontal datum that is substantially parallel to a longitudinal axisof the barrel, and substantially perpendicular to the planes of the atleast two supports.
 4. The tool of claim 1, wherein at least some of theplurality of spokes are removable from the hub and are adjustable inlength.
 5. The tool of claim 1, wherein the mid support comprises sixspokes extending outwardly from the central hub, each of the six spokesbeing configured to contact the inner surface in a region generallycorresponding to a position of a segment of a six-segment mandrel uponwhich the composite barrel was fabricated.
 6. The tool of claim 1,further comprising a second end ring, removably attachable to the secondend of the composite barrel, having a perimeter that is substantiallycongruent with the second end, configured to maintain a shape of thecomposite barrel.
 7. The tool of claim 1, wherein the first end ringcomprises a plurality of releasably attachable arcuate segments, eacharcuate segment comprising an outer ring segment, an inner ring segment,and a spoke interconnecting the outer ring segment and the inner ringsegment.
 8. The tool of claim 1, further comprising a moveable cart,having a plurality of supports configured to contact and support theouter surface to substantially retain a nominal shape thereof.
 9. Thetool of claim 1, the first end ring further comprising a slot configuredto receive a front edge of the first end of the composite barrel. 10.The tool of claim 1, wherein the plurality of spokes extending outwardlyfrom the central hub are configured to telescope in length.
 11. The toolof claim 1, wherein each of the plurality of spokes extending outwardlyfrom the central hub further comprises a bearing surface on a distal endof the spoke.
 12. The tool of claim 7, the plurality of outer ringsegments further comprising a slot configured to receive a front edge ofthe first end of the composite barrel.
 13. The tool of claim 12, whereinwith the front edge of the first end of the composite barrel received inthe slot of the outer ring segments each inner ring segment and spokemay be selectively removed while the plurality of outer ring segmentsremain attached to the first end of the composite barrel via the slot.14. The tool of claim 13, wherein a platform may be extended into thebarrel section with the inner ring segments and spokes removed.
 15. Thetool of claim 8, wherein the plurality of supports of the movable cartconform to half a circumference of the composite barrel.
 16. The tool ofclaim 8, the cart further comprising a plurality of wheels connected toa bottom surface of a frame, wherein the plurality of supports of themovable cart further comprise a plurality of upstanding supportsconnected the top surface of the frame.
 17. The tool of claim 16,wherein the plurality of upstanding supports are attached to each otherby a plurality of longitudinal rods.
 18. The tool of claim 8, whereinthe shape of the barrel includes a taper.
 19. The tool of claim 18,wherein the plurality of supports of the movable cart conform to half acircumference of the composite barrel.